1. Field of the Invention
The present invention relates to a hinge for furniture of the “frame” type provided with an improved structure and low thickness.
2. State of the Prior Art
For furniture built following the known load-bearing front frame system (widespread above all on the American market), single-pin hinges provided with position adjustment are more and more often required. The maximum adjustment capability is represented by the possibility of moving the furniture door in the three orthogonal spatial directions. To obtain this type of adjustment in a correct manner the hinge must be provided with three distinct operating members.
A further requirement consists in reducing the hinge thickness so as to obtain a minimum bulkiness inside the piece of furniture. The last-mentioned point is of great importance in making furniture for the American market for example, where the “frame” type construction already constitutes an important reduction to the piece of furniture opening.
A typical hinge construction for the frame system comprises a base portion to be fastened to the piece of furniture and pivotally mounted to a hinge box to be embedded into the furniture door. For maximum adjustment, the base portion is formed with two elements or plates slidably coupled with each other by a cam (or a screw) to supply front adjustment of the hinge. The innermost element is screwed on the frame edge by a fastening screw enabling vertical adjustment of the hinge position. The outermost element has one end bent at a right angle slidably supporting an arm pivotally mounted to the box (again with a cam or screw), so as to also enable a side adjustment of the position.
For reasons connected with the frame sizes, the cam for adjustment between the two base elements is usually located behind the fastening screw seat of the inner element on the frame. Therefore, riveting by which the cam axially locks the two components is not sufficient to ensure a good holding between the two components because said cam is disposed too rearwardly.
Consequently, for steady fastening it is necessary to create another coupling point on the forward part of the base relative to the fastening screw. This coupling must lock the two base components in the direction of the cam axis and, simultaneously, allow free longitudinal displacement of the two components for front adjustment. According to the known art, this coupling is obtained through formation of a pair of transversely aligned holes in one of the two components (in the fixed part of the piece of furniture, for example) and a pair of slots aligned with the holes and elongated in the front adjustment direction in the other component. A pin is inserted through the holes and slots and locked to the holes for transverse sliding along the slots, so as to obtain fastening between the two plates while at the same time maintaining a possibility of adjustment between the two parts of the base.
This solution however has some drawbacks. First of all use of another component (the pin) is made necessary so that the pin cost and the difficulties and costs for mounting of the pin are to be added.
In addition, for clear die-forming reasons, the hole must be made to a suitable distance from the upper wall of the fixed plate (the material width between the hole and edge should not be smaller than the material thickness). Due to the above, the overall height of the movable plate and therefore the hinge bulkiness within the frame opening cannot go below a minimum value (usually not less than 8.5 mm).
It is a general aim of the present invention to obviate the above mentioned drawbacks by providing a hinge of the frame type offering wide adjustment possibilities, while having a reduced thickness and being at the same time of easy and cheap construction.